It is known that surfaces of workpieces, but also skin surfaces, can be advantageously treated in various respects by plasma discharges. Surfaces of workplaces can be activated for a subsequent surface treatment, for example coating, in order to allow the coating to adhere better. It is further possible to clean surfaces with plasma discharges, for example to remove layers of oil.
A dielectrical barrier plasma discharge further allows skin surfaces to be safely treated. As a result, wound areas can be allowed to heal more quickly, the skin surface can be activated for improved absorption of active skincare or healing substances etc., for example.
The problem of being able to carry out plasma treatment which is as uniform as possible arises with surfaces which have an irregular three-dimensional shape. DE 195 32 105 C2 makes provision for a negative to be formed with the dielectric from the surface of the workpiece, said dielectric therefore comprising a plastic which can be shaped, for example can be pressed or thermoformed. In this case, provision is further made for an intermediate layer to be used, so that the dielectric can be shaped immediately at the surface of the workpiece with the intermediate layer. The intermediate layer is then removed in order to ensure there is an intermediate space, in which the plasma can form, between the dielectric and the electrode. On its face which is averted from the surface which is to be treated, the dielectric is coated with a conductive material which forms the electrode and to which the required high-voltage can be supplied in the form of an alternating voltage.
An electrode arrangement of the kind cited in the introductory part is known from DE 10 2009 060 627 A1. In the case of this electrode arrangement, the dielectric is formed by a flexible flat material which, on its face which faces the surface which is to be treated, is provided with a structure in order to form air guidance regions when the dielectric rests on the surface which is to be treated. The flat electrode is of flexible design and is fastened to the dielectric such that a layer of the dielectric shields the electrode from the surface which is to be treated. In particular, the electrode can be completely surrounded by the material of the dielectric, wherein only a high-voltage connection is routed out of the dielectric. The known electrode arrangement is particularly suitable for treating the skin surface of a human or animal body for carrying out a therapeutic or, in particular, cosmetic treatment. Owing to the resulting improved absorption capacity of the skin for active cosmetic substances, cosmetic treatments, such as smoothing out wrinkles, reducing the size of the pores etc., are possible in an efficient manner. Furthermore, a bactericidal and fungicidal effect of the plasma treatment can also be utilized for treating healthy or wounded areas of skin. The flexible design of the known electrode arrangement allows adjustment to the irregularly shaped surface. If elastic restoring forces are not excessively high in this case, the electrode arrangement maintains its deformation. However, the ability to adapt to small local irregularities of the surface is limited in this case.